Tip: How I fitted my Pepto Pink Cowl

Brantel · #1 10-14-2008, 06:33 AM

Not much info on here relating to the new Pepto Pink Cowl and its differences with the older ones so I will post pics of how one man is fitting his. I am using the tried and true hinges all around. Cheap and it works!

First I had to simulate the prop spacer I do not have yet so I picked up some 3" 1/2-20 fine threaded bolts from the hardware store. Along with the large spinner washers that come in the finish kit, I used these to attach the spinner backplate.

I cut some PVC pipe to make the 2-1/4" spacers. I am going to have a fixed pitch prop. It is my understanding that if your using a CS prop, you need a different length spacer.

I then used a couple old paper back books as a spacer for getting the top of the cowl aligned with the spinner. I just kept taking pages from the book and fitting the top cowl till the spacing was correct.

I then cut and drilled the hinges for the top. I spaced them right at the edge of the edge distance requirement for the holes in order to hide as much of the gap as possible between the cowl and the firewall area skins.

I drew a line 2" back from the front edge of the firewall skins, set my spinner to cowl gap at 1/8" and then marked the line onto the top aft side of the cowl. I then cut the top aft end to this mark.

Once this was fitting nice, I set the gap at 1/4" at the front and sanded in a 1/16" gap at the back for paint. I used a 16" long board with 60 grit glued to it for the sanding to ensure a nice straight edge.

Brantel · #2 10-14-2008, 06:34 AM

I have the typical problem of fits nice a the top but runs away at the center.....Will require building out later....

The spinner is fitting pretty concentric to the cowl at this point.

Next I moved on to getting the nose to fit together and round.

I took a Dremel and sanding drum and cleaned up the inside of the top at the overlap areas.

I also took a file and cleaned up the molded in flanges at the center of the bottom at the overlap areas.

In order for the two to go together, I had to mark a line so I would know how to cut the outsides of the inlets on the bottom cowl. I put a straight edge on the molded in flanges of the center of the bottom half and extended this line out to the outside of the inlets. I cut this off at that point but just to outside of the curve because I did not want to cut any off the sides at this point.

Brantel · #3 10-14-2008, 06:34 AM

I was then able to get the two halves together pretty nice at the front. It will require some tweaking to get the seams perfect but so far so good. I did not want to drill any side holes yet so I just joined them with a temporary hole at the front. This holds them together and pulls them into each other. Problem with this is that the clecos will hit either the spinner backplate or the starter gear/flywheel.

Once this was done, I hoisted the bottom up into place the best I could using a strap and a bungee cord or two. The goal was to get it close enough to know where to cut for the gear legs.

I then marked a cuttout on both sides of the bottom for the gear leg clearances...

And cut them out..They will need opened up more for brake lines etc. later.

Brantel · #4 10-14-2008, 06:36 AM

With that done, I was able to pull the bottom up into place to meet the top.

I just let the sides overlap the firewall and the top cowl all around. The front was able to be pulled into position. I used a strap and a bungee to hold it in place.

The fit at the outsides of the inlets at the seam don't look too bad at this point. Should get even better once the sides are not overlapping each other....

This will take some fill work to build it out even. At this point once I set the 1/16" paint gap at the back, it has about a 5/16" gap at the top. I do not want it any closer because that makes the top hard to get on and off later. As you can see the front is not molded properly.

noelf · #5 10-14-2008, 07:37 AM

Brian, I like your work...well done.

Just a couple of comments: from your pictures, the "gap" area between the prop spinner backing plate -to- fiberglass nose circle... I have seen some fiberglass spinners extend beyond the backing plate. This has the effect of closing up the gap. Just something else to watch for.

The other comment is the edges of the upper and lower cowling halves, where they come together behind the prop spinner plate. You had commented that you will address that area later. This area is completely hidden by the prop spinner and backing plate. You really do not need to do anything here. If you do trim for a uniform edge, only you will know and be able to smile in the fact that you left no detail undone.

allbee · #6 10-14-2008, 08:03 AM

I would like to add that the tools I used to fix up or make fit that center section were the cutting wheels like used on the canopy, I use the 3/32 wheels from 3M. Next I used a carbide bur, round nose tree, I think 3/8, in fact I use this thing so much for opening holes in aluminum, I use this on my air drill. Make sure and do this part with the cowl standing on end on the floor. When you get to putting the hinges on, do that on the floor with the front facing up, sitting on the floor, way eisier than fighting the on plane thing. The one thing that didn't come out right on my cowl and I noticed it on another is the line where the top meets the bottom in the center where the 3 screws go, kind of going up with an opening twards the aft edge. Good luck and have fun.

allbee · #7 10-14-2008, 08:24 AM

Oh, one more tip. On the front of the cowl where the two meet around the air inlets. Make sure and bring the bottom cowl forward enough to allow the lower cowl to take up the space. Meaning you will have a lower lip under hang. You see the lower cowl has extra meat there and if you wait until later after you have the hinges in and all put securely into place, take the carbide bur on an air drill and smooth out and match the top cowl, you don't have to do any lay up to match things up. Takes about 20 seconds with the carbide bur to make things looks real nice.

Another tip is to make a straight line down the side before sanding. Take some tape, masking or like, and run it down the side overlaping the area that you want to sand for a straight line, than take a piece of aluminum that is thin and long with a nice straight cut. Put in over the tape where you want the sand and secure it in place, either hold it with a friend helping or tape that also. Now take a straight edge razor blade and cut down the edge into the tape. Now remove the excess tape and you now have a straight line to sand to.

az_gila · #8 10-14-2008, 09:29 AM

...using the book as a variable thickness spacer.

Finally, a use for all of those Yellow Page directories that keep getting dumped at our mailbox....

174Bob&Nancy · #9 10-14-2008, 06:56 PM

I thought those were his old Gleim instrument books and study guide,.......

Brantel · #10 10-15-2008, 06:25 AM

Quote:

Originally Posted by 174Bob&Nancy

I thought those were his old Gleim instrument books and study guide,.......

Did not need any of those, I had a super instrument instructor that taught me all that stuff, I can get you his phone number if you like. You have to watch out though, he is one of them crazy homemade airplane builders and has a thing for old round motors!